


Made For it

by unsettled



Category: Iron Man (Movies), Marvel Cinematic Universe, Spider-Man (Tom Holland Movies)
Genre: Alpha!Peter, Alpha/Beta/Omega Dynamics, Breeding Kink, Dead Dove: Do Not Eat, Dirty Talk, Getting Together, Guilt, Incest, Knotting, M/M, Mating Cycles/In Heat, POV Tony Stark, Parent/Child Incest, Peter Parker is Tony Stark's Biological Child, Peter is 15, Post Mpreg, Underage Sex, even more literally since Tony's an omega, omega!Tony, prejudiced behavior towards alphas, referencing mpreg
Language: English
Status: Completed
Published: 2021-01-01
Updated: 2021-01-01
Packaged: 2021-03-10 17:47:38
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 1
Words: 8,180
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28471140
Author URL: https://archiveofourown.org/users/unsettled/pseuds/unsettled
Summary: Tony has never had the patience to deal with alphas. Too bad that his son just presented as one. But there's no way Tony is ever going to let Peter know how upsetting that is; his kid is still mostly perfect.It is too bad, right?
Relationships: Peter Parker/Tony Stark
Comments: 20
Kudos: 248
Collections: 2020 Marvel Holiday Secret Santa





	Made For it

**Author's Note:**

  * For [LivviBee](https://archiveofourown.org/users/LivviBee/gifts).



Tony has never had the patience to deal with alphas.

Honestly, he just can’t stand them. Always acting like they know best, don’t worry your pretty little omega head about it. Pushing their way into everything, trying to take over and dismiss Tony as unessential for anything of actual importance. 

Fuck them. Just because Tony’s an omega doesn’t mean he can be handled like that, doesn’t mean he’s going to put up with it. Being an omega doesn’t mean he wants to be under someone’s thumb and it sure as hell doesn’t mean he _needs_ an alpha. 

There isn’t an alpha out there that actually knows what’s best for him.

Even for Peter— sure, he’d needed an alpha’s sperm for his kid, but he had the resources to go for artificial insemination. The take rate for male omegas is awful, but Tony’s never relied on luck. He has JARVIS. 

Is it strange to have his AI pick out the best possible candidate for Tony’s baby? Maybe. Is it invasive for JARVIS to consider any alpha, whether or not they’ve actually donated? Probably, but the winner had been more than happy to provide a sample once Tony had thrown enough money at him, and Tony hadn’t even had to meet him. Had even been willing to sign away all their rights as a mate and a parent for a little extra. 

Does it result in Tony taking on the very first try? Absolutely, and that makes it worth every single penny. Because he gets Peter out of it, gets his wonderful, perfect kid. Smart and sweet and stubborn _( you take after me so much,_ Tony’s started telling him when they fight, and it generally makes them both grin). Tony couldn’t ask for a better kid in any way; he loves Peter more than anything in the world.

Then— then Peter turns fifteen. Presents a few months later, earlier than most of his year mates. 

As an alpha. 

The first Tony knows of it is when he comes home and smells… something off. Something viscerally wrong, disgusting. Something that only gets worse when he goes into the living room and finds Peter hunched over on the couch, a little ball of misery. 

“Peter?” Tony says. He’s still supposed to be in school and Tony doesn’t think he got a call about Peter being sent home. “What’s wrong?”

Peter looks up, red eyed, upset. “I’m sorry,” he says, offering up a piece of paper. “I— it happened at school and the nurse ran the test and it’s— I’m—”

Tony doesn’t need him to say it; he knows what the red header on the test results means. Knows what that smell is now, knows why he feels on edge in his own home. Peter’s an alpha. Peter’s—

Peter’s shaking. “Dad,” he says, “I didn’t— I didn’t mean to! I don’t _want_ to be an alpha! I’m sorry!” He bursts into tears and fuck, it doesn’t matter how awful Peter smells now, Tony can’t just let his baby cry all alone like that.

“Oh kiddo, no,” Tony says, kneeling in front of Peter and grabbing his hands. “It’s okay. It’s going to be okay.”

“But you hate alphas!” Peter wails. “You hate them so much and now I’m one and— I’m sorry, please Dad, I’m so sorry.”

Fuck, _fuck._ “I don’t hate you, sweetheart. I could never hate you.” He tugs Peter closer, Peter clinging, sobbing against his shoulder. “It’s not your fault, I know that. I know you didn’t want this, but… it’ll be okay in the end, I promise. You’re going to be okay.”

*

It’s rough at first. 

After Peter gets through the first stage of his presentation, his scent settles. Grows, into that thick, bitter, sweet scent that clings to the back of Tony’s tongue. It’s awful, and Tony can’t escape it; it’s everywhere in the house, and all over Peter, over everything he touches. 

Peter can’t help it. He knows this, and he’s not going to make his son take blockers just because Tony has a— a thing about alphas. He’ll get used to it. He’d told Peter it wasn’t his fault and it’d be okay, and he’s going to do his damnedest to make Peter believe it. 

He’s never going to let Peter know how unpleasant it’s become to even be in the same room as him, much less it next to him, or to hug him and kiss his forehead and treat him just like Tony always has, because Peter is taking this badly. He’s distressingly fragile about this, and Tony’s worried. It’s his own fault, with the way he’s talked about alphas all of Peter’s life, but he’d never thought— well, it doesn’t matter now. He’s just got to try and fix some of the damage he’s done. 

It’s not Peter’s fault he’s not quite so perfect anymore.

So, it’s rough at first, but slowly, things ease. Slowly, Peter’s first rush of scent dies down, mellowing into something not quite as awful. Starts to take the influence of Tony’s, softening a little, becoming more familiar. Not nearly as comfortable to be around as he used to be, but still something Tony finds easier to tolerate.

Slowly, Peter becomes more comfortable with his secondary gender, and Tony— Tony works hard not to think of Peter like that. To not apply those stereotypes—are they, though, Tony wonders, if they’ve been borne out every time he’s dealt with an alpha—to Peter. He loves Peter, and he’s never going to stop loving Peter, no matter he’s become. 

And then Tony has a heat.

Tony doesn’t even think about it; it’s never been a problem before. When Peter was younger, Tony would send him for a long weekend at Uncle Rhodey’s and grit his teeth and suffer through it. Sometimes he broke, when the heat aids weren’t enough and he was so desperate he couldn’t stand it. Would hire a heat companion, the lowest rated alpha they could find, one willing to shut up and take orders.

The need quiets as he gets older, thank god, and it had gotten to the point where he could nearly ignore them. Could just spend a few hours knotting himself once Peter had gone to bed and keep going like normal the rest of the time. Maybe a little more irritable, a little tired, a little achy, but just fine, and Peter knew by then to just be a little more forgiving for those few days. A little kinder, even. 

Had actually been really good about it the last few years. Been cute, even; had put on Tony’s favorite shows, had tried to cook things Tony especially liked (or order things he did, when the cooking failed spectacularly a few times. He definitely got that from Tony.), had practically bullied him into using the jacuzzi when Tony complained too much once about hurting all over and getting old. Had just… attempted to pamper him a little bit, adorably.

Tony won’t lie; he’d never let an alpha do that for him. He hadn’t wanted to give them ideas. But it’s always been fine for Peter to do it, and it’s been a little comforting. Peter’s just a good kid. 

But this time— 

This time, his heat hits him harder than usual, all the aches and pains and itchy, burning want that he’d thought he’d mostly left behind. This time, when Peter comes home from school, Tony knows without seeing him, hearing him. He _knows,_ because the second Peter walks in—

He doesn’t smell terrible anymore. 

Fuck, he smells good, so good, insanely good. The best thing Tony’s ever smelled, and that base part of his brain wants to just bask in it, cover himself in it. Tony freezes in the doorway of the kitchen; he doesn’t even remember getting here. 

He stares at Peter and Peter stares right back, eyes wide and darkening, his scent rising in response to a heat. 

Tony swallows, hard. “Peter,” he says. “I think you should go spend a couple days at Ned’s. Or Rhodey’s, or— or even Nat. Just. Not here.” 

Peter blinks at him slowly. “I don’t have to,” he says. 

Yes, yes he does. “I want you to,” Tony says, and he knows it’s going to hurt Peter; there it is, that little flinch. Anything he can do to get Peter out of the house is going to be worth it, though, because this— this is not supposed to happen. His body is not supposed to recognize his fucking son as a good potential mate.

“Are you sure?” Peter asks, stepping forward, and Tony shudders, his scent deepening, spreading. Suffocating. 

“Please,” Tony croaks, and Peter nods. Practically flees, and Tony has the horrible realization that Peter might have felt something of the same. 

It’s not a good heat. 

*

Things get a little awkward. 

They avoid talking about it, completely, but… well. Tony isn’t going to stop having heats, after all. And Peter— Peter is stubborn. So stubborn, like Tony doesn’t know where he got it from, like Tony hasn’t encouraged it. 

Peter loves him and hates to see him hurting. So the next time, when Tony tells him to go— Peter squares his shoulders and says no. 

“Last time,” Peter says, “I came home and you’d barely eaten. You slept for almost the whole day after and you looked awful and you smelled—” he stumbles to a halt, blushes. “You smelled wrong,” he says after a deep breath. “Like you were sick. It— it scared me, Dad. I don’t want to leave you alone like that.”

“I don’t have to be alone,” Tony says. “I can— I can hire a companion.”

Peter frowns, staring down at the floor. Crosses his arms. “You’d hate that,” he says, very small. 

Yeah, Tony would. Has, in the past. It’s better than the alternative though. 

“Please,” Peter says. 

“I just don’t know if it’s a good idea, kiddo,” is the most he can manage without— without saying something heading into dangerous ground.

“It’s not a problem for most people,” Peter mutters, and Tony doesn’t want to be the one to point out that apparently, they aren’t most people. 

He caves. 

It’s an even worse heat. Oh sure, this time he doesn’t spend the entire time curled up in bed, frantically fucking himself with the largest knot he has and still feeling empty and desperate and abandoned, barely dragging himself to eat or clean up a few times, feeling sick, feverish, the whole time. And Peter’s downright annoying about attempting to take care of him, bringing him food and pestering him about not hiding away the whole time and making Tony take care of himself some more, even if it’s mostly to avoid the shame of Peter seeing him like this. 

But it’s torture, having Peter in the house. It’s _torture,_ having what his brain seems to think is the perfect mate right there and not available, not doing anything. Having to tell himself over and over, in the worst of his heat when he can barely think straight anyway, that he can’t have this alpha. He can’t have Peter. Can’t have his son, fuck.

This is one of the many, many reasons Tony hates alphas. Because they do this bullshit to him, fuck with his head and make him want things, make it so hard to control himself. Make him consider things he never would. 

He wouldn’t. 

This is why he hates alphas, Tony thinks, the heat after that, Peter insisting that it had been fine last time so he’s staying again. This is why, he repeats in his head, making himself wait until Peter’s gone to bed before he fucks himself with his newest aid, larger than all the others, with all the bells and whistles to make it seem like a real alpha’s knot. 

This is fucking why, he tells himself as he comes again and again and again, clenching around it and muffling everything coming out of his mouth in the pillow; because they make him do this, want this. Make it so easy, so good, to imagine Peter fucking him, knotting him, filling him up and biting him, god, fuck. Make him moan _Peter_ into his bedding; whisper, hopeless, desperate, _please, Peter please, need you._

Because they make him not himself. 

But he’s not going to stop having heats, so he has to— has to just find a way to deal with this, a way that leaves him able to still look Peter in the eye after his heat’s passed. They’re not going to stop.

Worse, so much worse, Peter starts having ruts.

The first one— the first one, Tony doesn’t even smell. The first one is an almost instant slide from normal—Peter a little testy and distracted but normal—to full rut, Peter’s scent sharpening, deepening, flooding over Tony strong enough to make his knees go weak, send him sagging against the counter. Peter’s staring at him when Tony looks over, a little glazed, heavy and intent like Tony is some sort of prey, and it’s horrifying to see that expression on his kid’s face. 

Tony freezes, not wanting to set Peter off in any way, and Peter closes his eyes. Inhales, long and deep, _scenting_ Tony, Jesus Christ. 

Opens his eyes, and there’s a flicker, a moment where he seems to realize what is happening, what he’s doing. Freezes too, and then—

Runs. 

He’s gone before Tony has a chance to move, a chance to even call after him, slamming out of the house without taking a single thing with him. Tony sits, shakily, and has a little breakdown. 

He doesn’t know how they’re going to manage this now. What the hell they’re going to do. Fuck, what Peter’s going to feel, when his rut is over.

Rhodey calls a few hours later, just to let him know Peter’s with him, safe and incredibly upset. “He won’t tell me anything,” Rhodey says as Tony clutches his phone, “but… well, he’s in rut, Tony. It’s probably his first, right?” Tony manages a noise that sounds like affirmation. “Right. I’m sure that’s it; they say it’s rough the first time. He can stay until it’s over. He’ll be fine; don’t worry, Tones.”

Too late. 

If he thought things were awkward after his heats, they’re so much more fucking awkward when Peter comes back two days later, rut scent gone. His normal scent nearly scrubbed as well, buried beneath heavily scented soap and— Tony sniffs, carefully, once Peter’s turned his back. His scent is so muted, metallic tinged, just _off—_ he took a blocker. He took a fucking blocker so his scent wouldn’t bother Tony as much.

Tony’s heart nearly breaks. “Peter,” he says. “Baby. Come here a minute.”

Peter’s wary when he walks over, ashamed. Stops, a little too far away. “No,” Tony says, and opens his arms. “Come here.”

“Are you sure?” Peter says, so quiet, and Tony’s heart does break, completely. 

“Oh, kiddo,” he says. “Yes, yes, I’m sure,” and he clings to Peter just as tightly as Peter clings to him. It feels like he hasn’t properly hugged Peter in months.

“I’m sorry,” Peter whispers. “I’m so sorry, Dad, I don’t know what happened. I don’t know _why_ but I’m sorry.”

“It’s okay,” Tony tells him. “It’s okay, it’s not your fault. We’re going to be okay.” He ducks his head, brushing his mouth right over Peter’s scent point. “I don’t want you to take scent blockers,” he says. “They’re not good for you, and you’re not— you don’t need to, Peter. I’m going to be fine without them.”

“I don’t want it to bother you,” Peter says, and Tony shakes his head.

“It doesn’t. It won’t,” he promises. “You’re more important to me than any of that.”

*

He doesn’t know how he gets through his next couple of heats. 

Peter stays, and stays, and Tony gets used to his scent there, during them. He starts thinking—

You’re not supposed to be ashamed of anything you think during heat, whatever it is, however wrong it is. Everyone knows it turns omegas into someone they aren’t normally, that those things don’t count as real wants. Still, Tony doesn’t think he should ever admit that what he’s started thinking about during his last few heats isn’t just Peter, inside him and under him and filling him up. 

It’s Peter, how Peter— Peter wouldn’t be one of _those_ alphas, would he. Peter’s stubborn and a little pushy sometimes, but he’d never try to take over, never think he’s better than Tony. Never try to push him, manipulate him into doing something he didn’t want. Wouldn’t try to mate him or breed him without Tony’s permission, and would never use him like a mindless fucktoy, a stupid little omega slut. 

No; Peter would be such a soft alpha, so willing and careful with Tony, so easy to control, to direct. So good at taking direction. 

Peter would be— _could_ be—the perfect alpha for Tony. He’d barely need any training to be exactly what Tony wants; after all, he already loves Tony. He already wants Tony. It’s like this is what he was born to be. 

It’s awful, but Tony’s still thinking it during his heats. Is still thinking it outside of his heats, day to day, watching Peter and seeing all the ways in which Peter would be perfect. He already smells like Tony. He already knows exactly what Tony likes. Knows how difficult Tony can be and isn’t bothered by it. And he’s gorgeous, he’s so fucking gorgeous, so tempting. 

He thinks Peter’s watching him a little too.

There’s something wrong about contact between them now. There shouldn’t be, but when they’re curled up together, watching TV; when Peter slides up behind him and hugs him; when Tony leans against his side when he corrects Peter’s work— those touches are off, are too much, too charged. Heavy with a kind of intent that does not belong there. 

Peter doesn’t leave during his next rut. Just stays in his bedroom most of the time, and Tony’s on edge the whole first day despite himself. When Peter emerges every now and then, he follows every move Tony makes, unmistakably hungry. 

Tony should feel hunted, should feel angry and horrified the way he had been the first time Peter looked at him like that. 

Oh, he doesn’t. Stares back at Peter on the second day, challenging. _What,_ that stare says. _You want something? Gonna do something about it?_

Peter ducks back into his room and hides, but his scent is thicker, coating the inside of Tony’s lungs. He’s not handling this as well as Tony’s managed his heats with Peter in the house. 

Not nearly as good at keeping quiet when he moans Tony’s name either.

The last day— the last day, Tony wakes up and feels sore, heavy. Lies there and thinks, sluggishly, a little too hot, that he really wants to curl up with Peter and waste the day on some TV marathon. Really wants to— 

Fuck, he thinks a second later. Oh, fuck; this is… not great.

Peter’s in the hall when Tony comes out of his bedroom. Close, like he was lurking, drawn in by the scent of Tony’s heat, and the scent of Peter, of Peter still in rut, hits Tony so hard he shudders. God, he _wants._

“Dad,” Peter says, his voice low, rough. “Dad, this—”

“I know,” Tony says, cutting him off. “I’ll just— I’ll visit Natasha for a few days.”

“No,” and Peter walks—fucking stalks—toward him. Backs him up against the wall, his hands on either side of Tony, trapping him. Tony feels frozen. “I don’t want you to go.”

“That’s just your rut talking,” Tony says. “That’s all.”

Peter shakes his head, slow. “No,” he says. “I’ve heard you, Dad. I know what you want when you’re in heat. I could give it to you.”

Tony swallows, his heartbeat pounding in his ears. He should be afraid, he thinks, distantly. He should be worried about what this alpha might do, might try and take, now that he’s got Tony nearly pinned, but— he doesn’t fear Peter. Never will. There’s just… heat, a sharp screaming hunger riding up in him.

“I’ve heard you too, kiddo,” Tony says.

“Dad,” Peter moans, swaying closer, nearly touching him. “Dad, please, please, I want— I know you don’t want an alpha, I know, but I’d be so good. I’d be so, so good for you, I promise.”

It’s too much, too much, and Tony has held out too long. Has stopped being able to beat himself up enough for the things he’s been thinking, for what he wants. “I know,” he says. “I know you’d be so good. Fuck, Peter; you’d be perfect, wouldn’t you. You’d be every last thing I’ve ever wanted in an alpha.”

Peter closes his eyes, letting out a long, shuddering breath. “Let me,” he says, his voice so rough they’re barely words. 

Tony doesn’t even bother to think. “Yes.”

He gets a growl from Peter for that, gets Peter pressing closer and kissing him, his hands all over Tony. Tony hooks his hand around the back of Peter’s neck and pulls him in, holds him there and kisses him deeper, again and again and again. 

“Peter,” he says once Peter’s pulled back a little. “Not here, kiddo. I’m not up for getting knotted anywhere but bed anymore.” Peter moans; yeah, he thought that might catch his attention. He’s still like all alphas in some ways. 

“Why did I even bother getting dressed,” Tony mutters, walking Peter back into his bedroom, shoving him toward the bed. 

Peter’s still watching him, so intently, but a tiny little smile creeps onto his face anyway. “So I could undress you?” he says, and fuck, he’s going to be cute about this. Of course he is; it’s Peter. 

He kisses Peter, hands up under his shirt. “Better get on with it then,” Tony says.

Oh, he’s seen Peter naked plenty of times, across all ages, and he’s sure Peter’s seen him naked a few times too. But this is completely different; this time, they’re looking. This time, they’re touching, and it’s so good, it’s everything Tony’s been wanting for months now, the contact he needs to settle his heat a little. 

They fumble their way onto the bed, tangled up on their sides, Tony’s hand sliding down to Peter’s cock as they kiss, and he loves the way Peter’s breath catches. Peter’s hand curls over Tony’s side, spreads across the curve of his ass, and then hesitates. He presses his fingers down and slips them a little lower, a little closer to Tony’s hole.

“Dad,” Peter says, “can— can I, uh. Before I—” He cuts off with a groan, and it’s adorable. “Oh my god, I’m going to be terrible at this.”

Tony nips at Peter’s lip, at the edge of his chin, teasing. Playful. “You’re going to be perfect,” he says. “And yes. Whatever it is, yes.”

“Fuck,” Peter whispers, and then he’s rubbing his fingers along the cleft of Tony’s ass, right over his hole, spreading around the slick that’s already leaking out. Presses one in slowly, watching Tony, and sure, Tony doesn’t need it but it still feels good to finally have some part of Peter in him. He’s still early enough in his heat that he can let Peter have this without immediately needing more. 

He scrapes his teeth over Peter’s neck, getting a shiver from Peter. “Gonna open me up for your knot?” Tony says, and Peter whimpers. “Come on, Peter, you can get more in me.”

Peter listens, pushing a second finger in so easily, and Tony loves how quick Peter is to obey; how easily, thoughtlessly he does. He’s not going to really challenge Tony in any of this. Is more likely than not going to let him take the lead—ask him to, even—just like he does anytime he runs into something new. He always brings those things to Tony, like he’s certain dad will know what to do. 

His slick is running down Peter’s wrist by the time he’s given in and gone for three, Tony grinding back onto them, his hand slow on Peter’s cock, mouth slow against Peter’s. So sue him if he’s a little distracted. 

“I’m going to need more than that,” Tony says. Pushes Peter over and straddles him, and the way Peter stares up at him is fucking addictive. The way Peter moans when Tony rubs his ass over Peter’s cock, when Tony slides down onto it, is even better.

“Oh _fuck,”_ Peter breathes out. “Dad, you feel so good I can’t even believe it.”

“Feel pretty good yourself, alpha,” and Peter’s fingers dig into his thighs, hard. “You like that, huh?” Peter bites his lip. “Like having an omega all to yourself?”

“Yes,” Peter whispers, and Tony— he was so sure Peter would be good for him, but—

“Do you feel it?” he asks, quieter. “There in the back of your head, looking at me and seeing an omega?” Peter’s breath catches, and Tony settles down on him, grinding slowly. 

“Does it make you want things?” Tony murmurs. “Make you want to just… get me under you, get me pinned and fuck me, make me beg for you knot? Make you want to get your mouth on me, make me bleed and bond me and break me in? Is that what you want, alpha?”

He hopes not, but he has to know before he ends up caught, has to know if the mistake he’s making is just that Peter is his son. Just, he thinks, fuck, just. 

Peter’s staring at him, his hands painfully tight and that dazed, heavy look gone. “No,” Peter whispers. “Dad— no, I don’t. I don’t want— am I going to? Is that what— is that all I can do?” his voice rising, anxious. 

“Oh baby, no,” Tony says, leaning down and kissing him. “Of course not.” Peter’s hands ease on him, and he draws in a shaking breath.

“Good,” he says. “I want— I want other things, not that. I just— I didn’t know, I’ve never—”

“I know,” Tony says. “Aren’t you lucky, getting me for all these firsts.” He raises his ass, starting to ride Peter slow, far slower than he really wants to. “So what do you want, sweetheart?”

Peter shakes his head, without words as twitches under Tony. It’s like getting Peter’s cock in him sets Tony off, brings all that want, that need from his heat back front and center, taking over his brain. “How about this,” Tony says. “This is what you want,” as he fucks down onto Peter, clenches around him. “You want that, want to feel me so tight all around your knot, don’t you,” and Peter groans, his hips jerking up, meeting Tony. “Want to feel me keeping you there, stuck with me.” 

He gets a hand on his cock and Peter’s eyes snap to it, his mouth gaping open as he stares. “You want to be caught by me; you know it’s true,” Tony says. “Want to know I wanted you, when I’ve never looked at another alpha.”

“Oh god,” Peter says, “yes, yes, you can catch me, Dad,” and it should sound like the cheesy line it is, like an alpha teasing, pretending they’d hold true to it when they’d been caught good and hard.

It doesn’t. 

Tony’s suddenly desperate for Peter’s knot, the need for it sinking into him and spreading; he presses his hands against Peter’s chest and starts riding him fast and hard, just like he’s wanted to for months. “God, Peter,” he says. “Want you in me, want you to knot me up good.”

“Dad,” Peter whines, “you can’t say that, fuck.”

“No?” Tony says. “I think I can say whatever I want and you’ll love it. And what I want is for you to fill me up, lock so tight not a single drop of come could get past. Come on, kid; show me you can be as good as you promised.”

Peter’s gasping, flushed bright red and thrusting up into Tony frantically. “Gonna,” he manages, and he’s got that glazed, heavy lidded look again, sinking deeper into rut, into the mindless animal hunger of it. 

“Look at you,” Tony says. “Is that all it takes, huh? Telling you how much I want you swelling inside me, stretching me out? All you need to turn into this needy rutting beast?” Peter moans, his fingers leaving bruises on Tony, fucking him hard. “You’re such a slut for an omega hole, aren’t you,” and it’s fucking perfect; he can feel the first swell against his ass, the barest bump of a knot starting.

“Tell me, baby,” Tony asks, “is it better that we’re who we are?” Peter’s staring up at him, hanging on Tony’s every word; Tony leans closer, wants to be sure Peter can hear him over the loud, messy sounds of them fucking. “Do you like it more, knowing you’re going to knot your dad? Gonna come in your dad, breed him?” and he doesn’t need Peter to say anything, not with the way his knot is growing, still sliding in and out of Tony, a little force to it now. 

“I mean, who could possibly know you better,” Tony says. “Or is it more than that, hmm? Do you like knowing that you came from me? Came out of me right where you’re about to come in me?”

Peter jerks so hard, his knot really getting with it now, barely slipping out of him on the next stroke. _“Dad,”_ he gasps. 

“You were always meant for this,” Tony tells him, starting to pant himself. “Meant from the start to be so desperate for me, so needy, just begging for an omega to fuck, to milk you dry,” and it hurts when Peter tries to pull out that time, his knot hitting the point where they’re already stuck together; Peter could come like this—Tony could let him—but it’s not good enough, would just be a waste to have a loose knotting.

“I didn’t even know it,” Tony says, “but I made you to be so fucking filthy, so perverted. I picked the best donor for you, wanted you to be the best you possible could, but you’re even better than I'd dreamed.” It almost catches, Peter humping against him the limited amount he can, whining pitifully; Tony leans down, pulling on the knot a little, till his face is right over Peter’s. “You need this,” he says, Peter nodding immediately. “Need to be caught so badly, baby. You’re going to wind up being one of those alphas they talk about, that just can’t get enough, can’t ever get enough of being in an omega. It’s going to be so easy to make you knot me again and again, as many times as I want.” 

He laughs suddenly, nearly dizzy with the possibilities that just opened in his mind. Kisses Peter hard, biting his lip. “Think you’ll knock me up?” Tony whispers, pulling back just enough to see Peter’s eyes, wide and dark, shocked. Wanting. “Gonna give me a grandkid to spoil rotten?”

The sound Peter makes at that is incoherent, but the way his knot sinks further into Tony says enough. “Like the thought of that, do you?” Tony says. “Guess we’ll have to keep trying till it works.”

He feels it catch, feels it swell inside him, fucking huge, _god._ Peter’s got the most perfect alpha cock, the best Tony’s ever had. “That’s it,” he gasps, “fuck, that’s it, kid. Just like that, oh god, you’ve got such a good knot, so hard, ugh!” Feels it twitch as Peter starts to come, as Peter jerks under him, sinking even deeper, settling in and shooting off in Tony. Some distant part of Tony nearly hums with satisfaction. It’s a tight lock, a good breeding; Peter’s going to seed him easily like this. 

That shouldn’t be appealing at all, but it really fucking is, Tony’s cock throbbing in his hand; a few more strokes, another little thought about Peter’s pup, _their_ pup, the best of all possible choices, growing in him, and he’s coming, clenching down hard around Peter’s knot. 

When he sinks down, ass pulling wonderfully at Peter’s knot, Peter wraps his arms around him. Kisses him, slow, messy, pretty fucking out of it, but to be fair, so is Tony. He closes his eyes, shoving his nose into Peter’s neck, mouth over his scent point. Licks at it and Peter moans, turning his own face into the same spot on Tony's neck, breathing hot and humid against it, and Tony wouldn’t say no if Peter bit down right now. 

He won’t, because that’s just… not how Peter is, but Tony wouldn’t say no.

Tony squirms on Peter's knot every now and then, unable to help it, needing to remind himself how good it feels, how tight it’s settled. Peter moans every time, clinging tighter. 

“Still okay?” Tony says softly, and Peter tilts his head back, looking at him.

“Yeah,” Peter says, a little slurred, but it looks like he’s hitting a lull in his rut. “I needed you so much, Dad. Wanted you so much. The way you _smelled—_ I was losing my mind. How could I even look at anyone else when you were there?”

He’s tracing his fingers over Tony's back, slow, mindless circles. “I know you don’t want an alpha,” he says, quieter. “I won’t be all like, super alpha though, I promise.” 

“You’re not an alpha,” Tony tells him. “You’re _my_ alpha.” 

“Fuck,” Peter murmurs, shivering. “Please— I can be your alpha. I can. I _will.”_

“You will,” Tony says, meaning it, making that commitment without a second thought. “You’re a dream come true, Peter. Perfect, so perfect for me, like no one else ever could be. You’re already mine, already made from me.” 

Peter moans, pressing his face harder into Tony's shoulder. 

They stay like that, drifting a little; it’s a hell of a catch, Peter’s knot not shifting in him even a bit, not shrinking at all. Tony wonders how long it’ll stay. If it’ll be this tight every time. 

He hopes so. Of course his son would do this well too.

It lasts and lasts, and— and Tony’s slipping back into heat, Peter’s knot still just as caught in him as before. God, this is going to be a wild heat. 

“You said,” Tony starts, Peter stirring slightly, “said you’d heard me.” He drags his nails down Peter’s side, slowly, just feeling how he presses up into it. “So were you making sure I heard you? Doing it on purpose?”

“Um,” Peter says. “I— maybe. A little. I mean, I— I didn’t want you to know? I felt so bad about it. But I still… really wanted you to know. Really wanted you to—”

“Wanted me to what?” Tony says, propping himself up a little so he can look at Peter. It might be nearly torture for Peter, but Tony can still get off like this, listening to Peter’s dirty little fantasies. Can still come all over Peter and all around his knot. “What were you thinking when you jacked off and came calling my name?”

“Omigod, Dad,” Peter mutters. 

Tony snorts. “Little late to be embarrassed, kiddo.” Twists, clenching at the same time, and Peter groans as his knot gets all that movement. “I wanna hear it; entertain me, baby.”

Peter wrinkles his nose, but his arms stay tight around Tony. “I— I was thinking about you—” He takes a deep breath, turning until his face is tucked against Tony’s neck. “Was thinking about you fucking me,” he says, just a little muffled, and that was not quite what Tony was expecting. 

“Yeah?” he says. 

“Yeah,” Peter mumbles. “You— you’d tell me I hadn’t earned the right to knot you yet. That I’d have to work at it, show you how good I could be.”

“Fuck, Peter,” Tony says, squeezing his cock. “How were you supposed to show me that, hmm?”

Peter seems to realize what Tony’s doing then, tucking his head in more and looking down. Reaches down a second later, his fingers brushing over Tony’s, over his cock. “All kinds of ways,” Peter says, wrapping his hand around Tony’s, pressing their fingers between each other’s, slowly stroking Tony’s, using their hands together. “Anything I could think of, Dad. Letting you fuck me anywhere you wanted, any way; blowing you, or sometimes you’d just fuck my face and come all over it,” and Tony groans, hips jerking into their hands and pulling at Peter’s knot in the same movement. 

“I’d think— I’d think about you tying me up on the bed, to it, telling me alphas couldn’t be trusted,” Peter says, hand moving faster, tighter. “Telling me you’d help me learn, that maybe if I did well enough, you’d ride me like that, still tied up, after you came in me.”

“Jesus,” and it feels so good, this dual sensation, Peter all over him, in him. “You’ve got a filthy mind, baby.” He nips the underside of Peter’s chin, licks it, just barely, and he doesn’t know if Peter will even understand what that means. “I like it, Tony says. “After all, I know where you got it from.” 

Peter huffs out this strangled laugh, his hand tightening around Tony’s cock. Moves faster as he starts talking again, Tony thrusting into it, closer by the moment. “You wouldn’t let me knot you even then,” Peter says. “You’d pull off as soon as I was almost there and make me come like that, play with my knot after until I felt like I was going to cry or pass out or something,” and he probably would. An alpha’s knot is so sensitive, not meant for anything but the warm, soft inside of an omega. 

Tony shudders. “Next time,” he tells Peter, “next time, sweetheart. When—oh, fuck—when I’m not in heat, when I can give you the full attention you should get.” He pants, rocking against Peter, clenching tight around him. “I’ll make you knot like that when I’m not in heat, because you haven't earned that yet, have you. God, I can’t fucking wait, wanna see what you’ve got in me.” 

He’s close, so close, Peter breathing heavy against his neck. “I should— Peter, baby, please.”

“Should what,” Peter whispers.

“Should get you like that,” Tony says, his eyes closing, right on the edge. “Get your knot popped and then compare you to some of my aids. See what you’re closest too and fuck you with that one.”

 _“Fuck,”_ Peter says, shaky. “I— I know I’m bigger than most, you’d have to— I don’t know if I could take one that big,” and Tony’s coming, squirming on Peter’s cock and twitching in Peter’s hand. 

Peter’s knot might have gone down a bit, he thinks as he lies on Peter, his brain most static and white noise. Just a few things, circling round and round— wait.

“Bigger than most?” Tony says. “How would you know, huh? You haven’t even seen the size of what I get in me.” 

It’s cute how Peter blushes, avoiding his gaze like he can pretend Tony isn’t there while he’s literally stuck on Peter’s cock. “Uh, I—” He squeezes his eyes shut, the rest coming out in a rush of words. “I snuck in once and found them and maybe played with them a little and that’s how I know.”

“You— you little perv,” Tony says, but it’s delighted. “Shit, Peter. That’s— I wanna say I can’t believe it, but boy can I. So what, you borrowed them for a bit? Or did you get off in my room and do your little comparison there?”

“Ahhh,” Peter moans, so embarrassed, but he brought this on himself. “It— it was when you went off to that conference overnight.” 

“So it was in my bed.”

“Maybe,” Peter says. “But, uh. Yeah. I did that, so I do know that I’m bigger than all of them except the new one, so—”

“Wait,” Tony cuts in. “Wait wait wait. New one? _New one?_ Peter Benjamin Stark, that was not a one time experiment, was it.” Peter’s got his face hidden, an arm thrown over it like that’s any actual protection. “How else would you know that any of them are new, hmmm? Unless you just happened to see what was there before I got it and after.”

He pushes at Peter’s arm until he can see one eye; waits. Peter opens it, eventually, squinting at him. “You sneaky slut,” Tony says. “You went back for more, didn’t you. How many times?” 

Peter shakes his head, his face flaming red. “Too many,” he mumbles. 

Tony opens his mouth, about to demand more details, when Peter’s knot slips. He shudders, feeling it get smaller by the second, sliding out of him and leaving him feeling empty. “Ugh,” he groans, and clings to Peter a little, Peter gasping sharply. 

Oh, he feels gross, god. A hot shower sounds amazing, but that would require standing, and walking, and just in general moving and all of that sounds awful. He sighs against Peter’s collarbone. “So which one was your favorite?”

“What?”

He nips Peter, lightly, but Peter still jumps. “Which heat aid?” he says. “I know you probably tried them all.” 

“They— uh, I— it’s—” It’s almost painful to listen to like this; Tony takes pity on him.

“I just wanted to find out which one I should use, when I get you knotted on one while you’re still caught in me. That’s all, baby,” Tony says. Grins. “But I can just pick one, if that’s easier.” Peter makes a helpless little sound. “How about the one that expands?” Tony asks. “Or— what about the one with a tube; I could fill it up and make it squirt in you. Could lick it back out of you after, even. What do you think?”

“Daaaaad,” Peter whines. “You— I can’t— oh god, whatever you want, please.”

Tony laughs at him. “You really are a slut for this,” he says, tilting his head up and kissing Peter. “Love you, kiddo.” 

“I’d like any of it,” Peter says. “Anything you wanted from me. Anything at all; I love you too, Dad, so much.”

“I know,” Tony says. God, he knows. This— if Peter hadn’t loved him, maybe he might have been able to hold out longer. 

If Peter hadn’t loved him, this would have gone so much worse. He sure as hell wouldn’t be kissing Peter right now, warm and soft. Wouldn’t be nipping at Peter’s scent point, teasing, pestering him until Peter huffs and squirms away. Wouldn’t have Peter following when Tony rolls off him, flops over again onto his stomach, face buried in his arms. Stretches a little, and Peter’s hands are on him, stroking down his side, over his head. Peter’s mouth is on him, trailing kisses across his shoulders, lingering for a moment at Tony’s scent point, darting out his tongue to taste it. 

Peter’s hand wanders lower, practically groping at Tony’s ass. Not that Tony can blame him for being tempted, but there’s something— he’s not sure it’s entirely sane, the wave of humor that hits him at the thought of it. Maybe just a little hysterical, he decides, and he’s going to blame that completely on his heat. It’s always made him overreact. 

“Dad?”

“Mmm?”

“Can— would it be okay—”

“Peter,” Tony says. “I told you. Yes. Whatever it is, yes. Carte blanche, kiddo.” 

Peter huffs. Mutters to himself, something Tony can’t quite make out, and then, at the end, “Fine.”

Fine what, Tony wonders. Peter’s hands are on his ass, spread across each cheek and pulling him open as Peter shifts on the bed, settling between Tony’s legs; maybe that was it, maybe Peter wanted to look. 

Or not, oh, _god,_ Tony jerking as Peter licks up the cleft of his ass, stopping right before Tony’s hole. Pulls back and licks another line up, a little to the side of that, and it takes Tony entirely too long to realize Peter’s licking up the come that’s dripped down Tony’s ass. Can he be blamed, really, for being a little distracted by the wet, soft heat of his son’s tongue _there,_ of all places?

“Fuck,” Tony gasps. “What the hell, baby, what—”

Peter pulls back, his breath hot against Tony’s skin when he answers. “I was going to ask,” Peter says, just a little sharp. “But noooo—”

“I’m not regretting that,” Tony says. “Just— Jesus, kid!” as Peter presses his mouth against Tony’s hole, licking at it. 

He doesn’t bother with words after that. It’s easier, better, to focus on the feel of Peter’s tongue against his skin, all along his rim and inside, firm and soft and wetter by the second as Tony starts slicking up again; he doesn’t know if Peter’s going to be able to keep up with it. 

So much better to dig his head and his knees into the bed and push up into Peter’s touch, into his mouth. Peter lets him, waits until Tony’s settled in and then keeps him there, his arms hooked around Tony’s thighs, hands on his ass. Buries his face as deep as he can and laps at Tony, eager and fucking hungry. Tony can feel every touch, every breath, every moan Peter makes, and he’s getting pretty noisy himself. “God, Peter,” Tony manages at one point, “where the hell did you learn this?”

Peter barely pulls back enough to answer. “Didn’t,” he says. “I just— wanted to.” Dives back in and Tony groans. 

“You’re filthy, that’s what you are,” Tony tells him. “Fucking nasty, baby. Of course you’re a natural at this, you— oh fuck, right there, kiddo, right— yeah, keep it up.” He’s not sure if he can come from this—hell, if he can even come again so soon—but he’s going to try. 

“It’s— it’s just ingrained in you, isn’t it,” Tony says. “Down to your bones, buried so deep, that you’re a slut,” and Peter moans into Tony’s skin. “Such a slut, such a good fucking slut, hungry for slick; you’re a disgrace of an alpha, you know that?” 

That gets him a huff, and then a hand on his cock. Tony almost tells him no, almost insists on testing this, but it feels so good and he just wants to come. He’s past caring how, just— “Come on kid,” Tony gasps, “come on, show me what you can do.” 

Peter keeps licking after Tony’s come, lighter, softer, but still going even when Tony starts squirming, too sensitive and worn out. “Peter,” he whines. “Baby, ugh, stoppit. I know you’re a slut for slick but enough.” 

There’s one more broad, long swipe of Peter’s tongue and then he’s pulling back. “It’s not my fault you taste good,” Peter says, and Tony laughs. 

Turns a little to look over his shoulder at Peter and doesn’t regret it; Peter’s face is red, his lips even redder, wetness smeared all over his mouth and chin and cheeks. Spit or slick or come, it doesn’t matter. “You think it tastes good because it tastes like you?” he asks, idly, watching Peter lick his lips.

“What,” Peter says, staring down at Tony’s sill spread open ass. “Because it’s my come I’m eating out of you?”

Tony snorts and Peter gives him a confused look. “No, dumbass,” Tony says, Peter scowling, “because you’re half me. More than half, technically.” 

Peter rolls his eyes, actually rolls his eyes, god. “Or maybe you just taste good, Dad,” he says, wiping the back of his hand over his chin.

“Well, come on,” Tony says. Crooks his finger at Peter when he frowns. “Let me have a taste, then.” 

Peter’s mouth drops open, and then he’s crawling up over Tony, making things difficult as Tony tries to turn over at the same time. Kisses him, pressing his tongue into Tony’s mouth, and honestly, Tony doesn’t care what any of it tastes like. Just wants this, Peter’s lips on his. 

“You know,” Peter says when he pulls away. “You’re kind of a slut too, Dad,” and the laugh slips out of Tony before he even thinks about it. 

“Guess it just runs in our genes,” he tells Peter.

“Yeah,” Peter says, nuzzling up to him. “I guess I had to get it from somewhere.” 

“Guess you did,” Tony says, and— maybe no one will ever understand, but this was the right choice. Peter was the right choice, was the alpha he’s been holding out for all this time. 

Of course he’d ended up carrying the perfect alpha for himself. This was always meant to be. 

“Love you, baby,” Tony tells him, soft, almost a whisper against Peter’s skin. 

“Love you, Dad,” Peter whispers back, and that’s what really matters, isn’t it.


End file.
